Fuel Tank Pressure Sensor: Description and Operation
FUEL TANK PRESSURE SENSORFuel Tank Pressure Sensor:
The Fuel Tank Pressure (FTP) sensor measures the difference between the pressure or the vacuum in the fuel tank and the outside air pressure. The FTP sensor mounts in the top of the fuel tank - sending unit.
The PCM provides a 5-volt reference and a ground to the FTP sensor. The FTP sensor provides a signal voltage back to the PCM that can vary between 0.1 - 4.9 volts. When fuel tank pressure increases, the FTP sensor voltage decreases. High pressure equals low voltage. When fuel tank pressure decreases, the FTP voltage increases. Low pressure or low vacuum equals high voltage.